Engines



3 Sheets-Sheet 1.

(N0 Model.)

J. D. GRAY'. GOVERNING MECHANISM FOR DIRECT ACTING ENGINES No. 581,346.

Patented Apr. 27, 1897.

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J. D. GRAY. GOVERNING MEGHANISM FOR DIRECT ACTING ENGINES. No. 581,346.

Patented Apr, 27, 1897.

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(No Model.) v I 3 Sheets- Sheet 3.

. J. D. GRAY. y GOVERNING MECHANISMI'OR DIRECT ACTING ENGINES. No.581,346.

Patented Apr. 27, 1897.

' IlNirnn STATE-s ATENT Fries.

JAMES D. GRAY, OF BALTIMORE, MARYLAND, ASSIGNOR OF TVO-'IHIRDS TOIVILLIAM B. PRICE AND ABRAHAM SHARP, OF SAME PLACE.

GOVERNING VlECHANlSlVl FOR DIRECT-ACTING ENGINES.

SPECIFICATION forming part of Letters Patent No. 581,346, dated April27, 1897..

Application filed June 30, 1896.

.To all whom it may concern:

Be it known that I, JAMES D.' GRAY, a citizen of the United States,residing in the city of Baltimore and State of Maryland, have inven tedcertain new and useful Improvements in Governing Mechanism forDirect-Acting Engines, of which the following' is a specification.

My present invention relates to a new and useful improvement indirect-acting engines designed to utilize fluid under pressure for thedevelopment of mechanical power, and especially to that portion of suchan engine which determines the travel and dwell of the piston relativeto the speed of the main shaft, and has for its object to improve uponthe construction shown and described in Letters Patent No. 533,290,granted to me upon the 29th day of January, 1895.

Vith these ends in view myinvention consists in the details ofconstruction and combination of elements hereinafter setfortl1,and thenspecifically designated by the claims.

In order that those skilled in the art to which this inventionappertains may understand how to make and use the same, I will describeits construction and operation in detail, referring to the accompanyingdrawings, forminga part of this specification, in whichh Figure l is avertical section of an engine built in accordance with my presentimprovement; Fig. 2, an enlarged section of the dashpot andgovernor-valve, showing said valve open, which is the position assumedthereby when the piston is freed and permitted to move downward; Fig. 3,a detail section of the governer-valve, showing it closed; Fig 4, abottom plan View of the valve-seat; and Fig. 5, a plan View of thechest, the cap being removed.

In carrying out my present invention I provide a suitable framework forthe mounting of the several operating parts of the engine, and withinsuitable bearings in this frame is journaled the main shaft A, uponwhich is mounted the fly-wheel B, of a size and weight to maintain themomentum imparted thereto by the operations of the engine. This shaft iscaused to revolve in the direction of the arrow by a clutch C of anysuitable design, but as the construction thereof forms no part of senaNo. 597,523. (No moda.)

this invention I will not describe it in detail, the only essentialbeing that this clutch shall grip the shaft when moving in onedirection, but be adapted to freely move in the opposite directionwithout affecting said shaft, or to permit the shaft to revolve thereinwithout affecting the clutch, the reasons for which will be hereinafterclearly seen.

The cylinder D is supported by suitable uprights, and has iitted thereinthe piston E in the usual manner, and from this piston runs thepiston-rod F, through a stuffing-gland, and this rod carries thecross-head G, said head being guided by the uprights, so as to move uponthe axial line of` the cylinder. The cross-head also carries suitableslippers fitted within slots formed in the clutch-arm, by means of whichmotion is imparted from the said head to the clutch-arm in bringingabout the rotations of the main shaft.

Suitable admission and exhaust valves are arranged within the chest H,and these valves are operated by the motions of the cross-head, so as tobring about the admission of live steam below the piston and the exhaustof said steam after being utilized at the proper times An exhaust-pipe Ileads from the chest, as also a branch J thereof, this arrangement beingutilized to balance Ithe exhaustvalve, and said exhaust-pipe passes tothe pipe K, which connects at L with the upper portion of the cylinder,so that when the piston has been moved upward and the steam which hasbrought about this movement is released from the lower portion of thecylinder it will gain access to the upper portion thereof through thepipe K, thereby counteracting the back pressure incident to theexhaustin g of all of the dead steam directly to the atmosphere.

The point at which the pipe K enters the cylinder is somewhat below theupper wall of said cylinder, so that when the piston is forced upwarduntil its upper edge passes this pipe the amount of fluid then containedwithin the upper portion of the cylinder will be compressed by thepiston and serve as a cushionfor arresting the movement of said pistonwithout shock to the engine. After the piston has moved upward, carryingwith it the cross-head, and thereby causing the IOO clutch to act uponthc main shaft to revolve the same, should the predetermined momentum ofthe iiy-wheel be then established, it is essential that the pistonremain in its elevated position and that it be not again operated untilthe speed of the fly-wheel has fallen below the pred eter min ed numberof revolutions per minute, and this is accomplished in the followingmanner: Mounted upon the top of the cylinder at a suitable heighttherefrom is a dash-pot M, and fitted therein is a plunger N, connectedby the plungenrod O to the piston E, so that said plunger will be causedto move in exact unison with said pis ton. A valve-chest P is located atone side of the dash-pot and has leading thereto from the lower end ofsaid dashpot the passage way Q and from the upper portion of the dashpot the passage-way R, and this last-named passage-way merges into thefunnel-shaped cap S, which has formed thereon the valveseat T, and isbolted to the chest so as to close the latter.

A valve U is fitted to the under side of the valve-seat T, and both thisvalve and the seat have formed therein elongated slots, which whenregistering permit the free passage of the liquid which is containedwithin the dashpot, but when these slots do not register the flow ofsaid liquid in the direction of the arrow in Fig. E2 is cutoff. Thevalve U is held against the seat by the semielliptical spring V, andthis arrangement permits of the liquid passing through the slots of thevalve-seat in the opposite direction of the arrow when sufficientpressure is brought to bear upon said liquid to overcome the resistanceoffered by the spring, since the valve will then be forced downward fromoff its seat.

In order that the valve U may be opened or closed as occasion requires,a stem VV is attached thereto, which passes without the valve-chestthrough the tube X and carrie-s upon its outer end the yoke Y. This yokehas att-ached thereto the platesprin gs Z, the latter carrying theweights a, and the opposite ends of these springs are secured to thepulley b, which latter is journaled upon the tube X and prevented fromlateral movement by the collar c.

Rotation is imparted to the pulley l) by the belt d, which also passesover a suitable pulley carried by the main shaft A. Thus when the speedof the fly-wheel is above the pre determined number of revolutions perminute the governor will be so revolved asV to cause the weights (l, bycentrifugal action to bow the springs Z, thereby forcing the stein XVinward and closing the passages through the valve-seat by moving theslots within the valve out of alinement with the slots in said seat,from which it will be seen that when the piston is moved upward,imparting the desired speed tothe fly-wheel, the liquid which iscontained within the dash-pot, and which I prefer should be oil, will beforced from the upper portion of said pot through the passage R anddownward through the openings in the valve-seat; but when the piston hasreached the limit of its upward stroke it will be there held against areturn movement by the plunger N, resting upon the liquid within thelower portion of the dash-pot, and this liquid will be preventedfromescape by the seating of the valve U, as before described. Nowsolong as the fly-wheel continues to revolve at the proper rate of speedthe governor will hold the valve U in its closed position, but shouldthe speed of this wheel fall below the predetermined speed thereof thedecrease in centrifugal action upon the weights a caused by thisdecrease of speed will permit the springs Z to move the stem W', andconsequently the valve U, outward,which will brin the slots in saidvalve in alinement with the slots in the valve-seat T, therebypermitting the escape of the liquid from beneath the plunger N to theupper portion of the dashpot, and this will permit the descent of theplunger, which will be then drawn downward by the weight of the pistonand parts carried thereby. During the downward movement of the piston,and consequently the erosshead, said head will operate the admission andexhaust valves in such manner as to close the latter and open the formerat the lower portion of its stroke, and the admitted steam will againforce the piston upward, causing theclutch to again operate upon themain shaft, so as to increase the rotations of the fly-wheel, which willagain increase the revolutions of the governor, thereby closing thepassages through the valve-seat T, as before described, and for thepurpose of again supporting the piston in its elevated position untilthe speed of the fiywheel has decreased below the predetermined point,when the action just set forth will again take place.

It is necessary after the piston has been cushioned at the upper end ofthe cylinder, as before described, to permit said piston to movedownward until its upper edge passes sufficiently below the pipe K forthe escape of the cushioning fluid, and this is brought about by therunaround c, which enters the upper portion of the cylinder at twopoints, said points being at a distance apart equal to the distancethrough which the piston must travel to release the cushioning fluid, sothat when the plunger has been forced upward by the piston to theextreme upper end of the dash-pot it is permitted to return downwarduntil registering with the lower entrance of the runaround on account ofthe liquid which occupies the daslrpot below the piston escaping throughthe lower entrance of the runaround and flowing into the dash-pot abovethe plunger'. I have also found in practice that it is desirable topermit the piston to fall rapidly after starting downward, and as theopenings in the valve U do not of necessity fully register with theopenings in the valveseat T when the governor first imparts a lon- IOOIIO

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gitudinal movement to the valve I therefore provide the longitudinalgrooves f in the walls of the lower portion of the dash-pot, so thatwhen the plunger N passes below the upper ends of these grooves theliquid below the plunger may escape around said plunger to the upperside thereof, thus permitting the rapid downward movement of the plungerand piston, which facilitates the operations of the valves and preventswiring of the admissionsteam.

From this description it will be obvious Jthat the piston will dwell inan elevated po'- sition so long as the fly-wheel is revolving at theproper rate of speed, and will only be caused to move downward andoperate the valves to bring about a further action upon the main shaftwhen said fly-wheel has decreased in speed below a predetermined point,the advantages gained thereby being that the wear and tear of the movingparts of the engine are greatly reduced in that they remain at rest,except when their movements are needed, and that the unnecessary use ofsteam is not occasioned.

In practice it has been found that an engine thus constructed willutilize the fluid which is admitted thereto for the operations of thepiston in the most effective manner, and when this fluid is steam orother eXpansible gas the expansion thereof may be so limited as toprevent its passing below an effective pressure.

It is to be noted that such an engine is especially adapted for usingnon-expansible fluids, such as water, in that the volume of Huid usedwill be in direct proportion to the amount of power generated, since thepiston will dwell when its movements are not needed, thus obviating thenecessity of filling and emptying the cylinder, which will greatlyeconomize the volume of fluid used.

Having thus fully described my invention, what I claim as new and usefulis- Il. In a device of the character described, a dash-pot, a plungersliding therein, a rod connecting the plunger with the piston of theengine, a by-pass connecting one end of the dash-pot to the other, avalve located in said by-pass, said valve adapted to allow the contentsof the dash-pot to pass in either direction when open, but in only `onedirection when closed and means controlled by the speed of the enginefor operating thevalve, substantially as described.

2. In an engine of the character described, a main shaft, clutchmechanism (for operating said shaft in one direction only, saidmechanism being so arranged as to permit the free :revolving of theshaft independent of the movements of the clutch, anintermittentlyoperated piston fitted to slide within a cylinder, meansfor controlling the admission and exhaust of fiuid to said cylinder, aplunger connected to the piston, said plunger being fitted within adash-pot containing a non-compressible liquid, a valve for controllingthe movements of said liquid, and a governor for operating said valve,the operations of said governor being dependent upon the speed of themain shaft, substantially as and for the purpose set forth.

3. In an engine of the character described, a main shaft jonrnaled in asuitable frame, a clutch mechanism for operating said shaft in onedirection, a cross-head adapted to impart an oscillatory movement tosaid clutch, a piston connected by a piston-rod to said cross-head, acylinder in which said piston is fitted to slide, valves for admittingand exhausting steam from the cylinder mechanism under the control ofthe cross-head for the operation of said valves at predetermined times,a plunger connected by a plunger-rod to the piston so as to move inunison therewith, a dash-pot in which said plunger is fitted to slide,said dash-pot containing a liquidsuch as oil-passages leading from theupper end of the dash-pot to the lower end thereof, a valve interposedbetween said passages for controlling the flow of the liquid from oneside of the plunger to the other, and a governor for opening and closingsaid valve, the operations of said governor being so controlled by therelative speeds of the main shaft as to cause the piston to dwell exceptwhen its movements are needed to maintain the predetermined speed ofsaid shaft, as specified.

4. In an engine of the character described, a main shaft mounted in asuitable frame, a momentum-perpetuator carried by said shaft, a clutchfor operating said shaft in one direction, a cross-head for operatingsaid clutch, a piston connected by a piston-rod to saidcrosshead, acylinder in which said piston is fitted to slide, valves for controllingthe admission and exhaust of steam to and from the cylinder, mechanismadapted to be operated by the movements of the cross-head for bringingabout the proper movements of the valves, a pipe leading from theexhaust to the reverse side of the piston and at a point below the upperlimit of the stroke of said piston, aplunger N, a rod connecting saidplunger with the piston, a dash-pot in which said plunger is fitted toslide, said dash-pot containing the proper quantity of liquid, arunaround so located relative to the movements of the plunger as topermit a sufficient downward movement of said piston to release thecushioning fiuid, a valve-chest P, passage-ways leading from each end ofthe dash-pot to said chest, a valve-seat formed upon the cap of thechest and having elongated slots formed therein, a valve also havingelongated slots fitted upon said seat, means for normally holding saidvalve in contact with the seat but adapted to permit said valve to beforced thereoff, and a governor connected with said valve, said governorbeing so connected with the main shaft as to open or close its valve bythe variance in the speed of said shaft, substantially as and for thepurpose set forth.

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5. In an engine of the character described, a dash-pot, a plungersliding therein, a rod connecting the plunger to the piston of theengine, a by-pass connecting one end of the dash-pot to the other, aslotted Valve-seat within the by-pass, a spring-pressed slotted valveslidable therein, a valve-stem journaled in the by-pass and slidable inslots ofthe valve and a governor operated by the engine and controllingthe valve, substantially as described.

6. In an engine of the character described, a dash-pot, a plungerslidable therein, a rod connecting the plunger to the piston of theengine, a by-pass connecting one end of the dash-pot to the other, avalve-chest formed in the by-pass, a slotted valve-seat in the topthereof, a slotted valve slidable thereon, a spring pressing the valveagainst the seat, a tube leading to the Valve-chest, a valve-steinslidable therein, slotted ears depending from the Valve slidable on thevalvestem and engaging nuts thereon, apulley j ournaled on the tube, abelt connecting the pulley to the driveshaft of the engine, a yokejournaled on the Valve-ste1n,sprin g-straps eonneetin g the yoke andpulley and weights on the spring-straps, as and for the purposedescribed.

7 In an engine, a 'valveehest, a slotted Valve-seat therein, a slottedvalve slidable thereon, a spring pressing the Valve against thevalve-seat, a tube .leading to the valvechest, a valve-stem slidabletherein, depending ears slidable on the valve-stem and engaging nutsthereon, a pulley journaled on the tube, a beit connecting the pulleyWith the drive-shaft of the engine, a yoke journaled on the Valve-stein,spring-straps connecting the yoke to the pulley and Weights on thespringstraps, as and for the purpose described.

In testimony whereof I have hereunto affixed my signature in thepresence of two subseribin g witnesses.

JAMES D. GRAY.

Witnesses:

S. S. VILLIAMSON, R. BRENT WALLING.

